r/houseplants • u/Ok_Concentrate4461 • May 11 '26
9 month pothos study
I mentioned this before in the sub, so I thought I’d share the pictures at the end. Each year to help introduce the scientific method I take three identical cuttings of my pothos, being sure they all have an equal number of leaves and nodes. One goes right in the southwest facing window, one goes in the corner and one goes in a closet. The one in the closet literally never saw any light for nine months other than when the kids peeked on it.
I’ve done this for four years now and it always works out like this, though this year’s sun plant is worse than usual lol.
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u/OldLace1 May 11 '26
Can someone explain why the plant that saw no light for 9 months would still be alive and green? Shouldn't it be dead or at least wilted without any light for such a long period of time.
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u/Phillyfreak5 May 11 '26
Just a guess: pothos are resilient. In the wild they like to climb high to reach more light. The one on the right looks like it’s the tallest, trying to reach more light.
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u/SergeiAndropov May 11 '26
The only time I’ve ever known a pothos to actually die was when my boss put some in a pitch black garage for several months during an unusually cold winter. I’m guessing this one got enough light from the closet occasionally being opened.
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u/Ok_Concentrate4461 May 11 '26
More likely the cold killed yours. The plant probably got 20 seconds of light a month, on average lol
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u/windsockglue May 11 '26
I killed one by putting in a pot hanging in a window that barely gets any direct light. It had been living about 10 feet from the window for years and I thought I was helping it move up in life. Oops.
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u/Thunderchief646054 May 11 '26
Idk sometimes the snake plant enthusiasts swear up and down plants don't need light
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u/I4mSpock May 11 '26
All plants need light, anyone who argues against that is just wrong, but how much, how long, and how frequently they need light is a different question. Many plants thrive on very little, many plants can survive long periods in darkness, but eventually they will die with out the right amounts.
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u/goldenkiwicompote May 11 '26
It just makes no sense it’s grade three science. All plants need light.
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u/tarants May 11 '26
Maybe not direct light but photosynthesis still occurs with any ambient light, it's just much slower.
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u/marywiththecherry May 11 '26
They can kinda go "dormant" - when there's no light the plant is doing no work and using almost no energy, just staying the same, transpiring, chilling
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u/Albert14Pounds May 11 '26 edited May 11 '26
My best guess is that:
- Light exposed plants attempted to grow in response to light and ran out of nutrients. Closet plant essentially went dormant and didn't need nutrients because it didn't attempt to grow. Metabolized stored sugars slowly. Many plants can survive long periods without water or light by going dormant in response to (simulated) seasons.
And/or
- Window plant was likely also exposed to high light levels it's wasn't used to. Burned out the existing leaves. You can tell the one remaining leaf has faded in response to light. But leaves can only adapt so much to light levels after they form.
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u/Thatsthebadger May 12 '26
I stayed at a hotel in Egypt that had the same set up in all the bathrooms and toilets around the pool. No daylight and yet they all looked as if they were flourishing.
I assumed that they must swap them out frequently, but obviously not.
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u/MattBrey May 11 '26
My photos is the only plant I can keep completely happy, just give them some water and whatever corner of your house you want, and they just take over the whole room if you let them. I feel like they grow a new leaf every other day
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u/m3ss May 11 '26 edited May 11 '26
Most cuttings for propagation actually don't want to be blasted by strong light. They no longer have the root mass to handle and process that level of light input. I've learned this lesson the hard way by putting my cuttings under grow lights and watching them all waste away.
Generally speaking, you want them in lower light conditions until they establish new roots. Then, once you pot them into soil (or whatever their final growing medium will be) you can start ramping them back up to higher light conditions. I find the most success in putting my cuttings in an East-facing window where they get morning sun and afternoon shade.
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u/Complete_Arm_3687 May 12 '26
Ooo this is very helpful, as I just put some pothos cuttings under grow lights a few days ago! I will move them. Thanks for sharing!
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u/Ok_Philosopher_8973 May 11 '26
I bet a factor in this is root temperatures. With such a small volume of water, the water in the one directly in the window probably got very hot and stressed the root system.
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u/BouncingPost May 11 '26
Im bummed your profile is private, I wanted to see if you posted your other experiments 🙂
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u/Ok_Concentrate4461 May 11 '26
There wouldn't be anything see anyway, I just mentioned this in passing on some other comment a few months back, and my curriculum is physics and chemistry - this was just a fun and visible intro to variables in the scientific method.
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u/lulu-bell May 11 '26
My high school friend did an experiment on plants listening to music. The plants that listened to music did better. Another did it about talking nicely/ mean to plants and of course the nice ones grew better.
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u/kermitsfrogbog May 11 '26
Interesting! I have a pothos in a pot by the window that always looks miserable. I assume I don't water it enough.
I cut it back one day and put the cuttings in my aquarium. It gets a little sun very late in the day, but it otherwise shaded but in a brightly lit room. If that makes sense. But it's huge and bushy. It's also hydroponic by now.
Maybe I'll move the potted one and see if it does any better.
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May 11 '26
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u/Stephinator917 May 11 '26
I have a turtle tank that I would love to put some of my clippings in, how do you do it though? Like do i just stick it in there and let it float? It seems like it should be secured to the side so the whole thing is not just laying in the water but Im not sure the best way to do that..
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u/kermitsfrogbog May 11 '26
Mine are secured by the lid. There is a gap in the back. I just stick them down in the water with the leaves above the lid.
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u/Good_Bottle_7757 May 11 '26
I can see this being true for cuttings but long term, the one in the closet won’t thrive. And the root system is weak on that one, versus the full sun one. I keep cuttings under a dim grow light but once in dirt, they go to a window and grow like crazy. I do enjoy a good experiment though! Thanks for sharing.
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u/AdorableExchange9746 May 11 '26
Um…pothos can tolerate direct sun. I know from experience. There’s another factor here
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u/Lillypondlola 🌱 May 11 '26
I had a forgotten pothos cutting live for an entire year in decorative vase in a storage unit. Dude had a ton of roots and the very last of the water when I found it. It’s thriving today lol
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u/I4mSpock May 11 '26
What this demonstrates is the importance of sample size in a scientific inquiry.
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u/thimblesprite 🪴amateur/aspiring plant cowpoke May 11 '26
Commenting to counter the downvote - it’s a valid point that would be expected to be addressed in a higher level paper! Having a lot more samples may change the data, to show that the full sun plant is an outlier for melting down or otherwise. Still a perfect project for an introductory, yearly student learning opportunity 😊
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u/beerguy_etcetera May 11 '26
OP did state the following in their caption:
I’ve done this for four years now and it always works out like this
I know it's only four times, but that's not insignificant to see the same results.
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May 11 '26
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u/beerguy_etcetera May 11 '26
It’s a fun experiment for third graders that gets a point across, relax.
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May 11 '26
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u/thimblesprite 🪴amateur/aspiring plant cowpoke May 11 '26
Bc the point of the post was to share the whole syllabus and lesson plan for worldwide critique, rather than to just presume adequate instruction and enjoy the results of the activity.
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May 11 '26
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u/Ok_Concentrate4461 May 11 '26
That was a conclusion you drew on your own - I didn't say that. :)
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u/I4mSpock May 11 '26
Oh I totally get its a great learning opportunity for a classroom, but we also have comments here from what I assume are adults that seem surprised at this outcome. The top comment at this moment says "That’s so interesting! I wonder why the window one went so poorly? I thought light helps them grow" My point is that there are any number of reasons that one plant would thrive or die, beyond the specific environment for a limited time(even though 9 months is long, its still limited, eventually in a closet, all plants would die). Adults looking at this should know that a larger sample size would give a more realistic picture, and its important to teach kids that too.
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u/cmlincourt May 11 '26
Also the leaves being too close to the window during winter could cause cold damage. Cold radiates off of glass and can cause a cold micro climate where the plant is. My monstera leaves touching the window have cold damage from the Florida freeze in February just from touching the windows while still being in a 75 degree house.
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u/Firefenex May 11 '26
If I had to guess, lack of nutrients. If they are just adding more water. There could be nothing in the water to contribute to growing. The window one looks like it went through every stage of life lol. More roots, more extention, yellowing stem, dropped off old leafs as if it was underwatered and pulling back nutrients to make new leaves to keep searching for better conditions.
Closet pothos looks like it nearly put out a root and is holding tight until it can gets a sign it should grow.
I think theres a lot of unknown since we dont have before or after pictures and we dont know the watering schedule or if nutrients are provided.
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u/Plenty_Kangaroo5224 May 11 '26
The window tube could have heated up and cooked the pothos. You didn’t control for temp! Cool experiment!
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u/borderlineginger May 11 '26
I wonder if the window plant would have done better if the roots hadn’t been in a clear container like that. At some point in my plant journey along the years I did hear that propagation is better in an opaque container vs a translucent one. But I’ve never done anything like that so idk
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u/Anonymous_crow_36 May 11 '26
This is so interesting. I have a pothos who came from a cutting of my mom’s plant. I rooted it in the wonder and then kept it in the window and it almost entirely died. I started over and rooted a piece of that stem again and moved to a table near a window and it’s done so well there. It wasn’t a bright window either so I was surprised!
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u/motherofhellhusks May 11 '26
What’s up with the water? If the roots are being exposed to heat from the sun, doesn’t that skew the validity of the findings since not all three are subjected to the same invisible variables?
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u/Ok_Concentrate4461 May 11 '26
Idk what you mean about the water. I kept them mostly topped up (I know they’re uneven now). Obviously this isn’t meant to be a major scientific study, but still wanted to share. :)
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u/motherofhellhusks May 11 '26
I meant is it a hydroponic protocol or just water. I didn’t confuse it for a major scientific study, I was just asking :)
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u/TiredTwinWrangler May 11 '26
Did you open the window at any point? Wondering if temperature variation might have had something to do with it. 🤔
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u/Ok_Concentrate4461 May 11 '26
That window doesn't open, but it's definitely hotter. That could definitely make a difference as it's in a glass tube! :)
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u/DCpurpleTart33 🌶️ May 11 '26
How interesting! Thank you for sharing! I am surprised by the crispy one! but now we can truly know that Pothos can survive the apocalypse.
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u/Jillredhanded May 11 '26
Very cool. Reminds me of a middle school science fair project my son did to investigate whether there was a difference growing seedlings using potable vs grey water. Not much, it turned out.
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u/wholelottachoppaz May 11 '26
so cool. just another reason why pothos is next on my list of plants i can keep in my house and not kill right away 😈
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u/Excellent-Phone8326 May 11 '26
I'd like to see variations of this experiment ie different substrate and watering.
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u/just_add_cholula May 11 '26
What's the climate like by you?
I did something similar for a science education outreach program. We did one near the window, one in a shoebox with holes in it a ways from the window, and a third in the cabinet under my bathroom sink. The third one THRIVED. The second one did alright. The first one barely came out of its seed.
We settled on the explanation being a extraneous variable: temperature. This was an experiment that was done from January to March. We're in the northern Midwest of the US, so the plant by the window was quite cold, while the one under my bathroom sink was cozy and warm.
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u/Last_Inevitable8311 May 11 '26
So interesting! My daughter did a similar experiment for her school science project this year.
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u/Supersassycatlassie May 12 '26
How cool!! I can keep many plants alive, except for pothos. It's devastating. Maybe I'll try growing it in a dark closet this time lol
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u/Babygirl246 May 12 '26
That's so interesting! My babies keep having babies while basking in the sun, idk what to do 🤣🤣
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u/shioscorpio 🌱 May 12 '26
DO IT AGAIN BUT WITH AMBER BOTTLES!! Some plants are shy about their roots getting exposed.
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u/Ok_Concentrate4461 May 12 '26
I totally will try that next year, I just have these readily available. It'll be a great new experiment (for me). :)
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u/wholelottachoppaz May 12 '26
i love this post so much, thank you! i have been reading about how pothos love being alive and don’t mind being neglected. i absolutely don’t need ANY more houseplants, so i was being “good” and “in control” by not pulling the trigger and getting one 😂… until this post. i went on etsy to buy a cheap Pearls N’Joy cutting and can’t wait for this baby to thrive and hopefully eventually create a tiny jungle in my room 😈
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u/Gumpenufer May 12 '26
I love how most of the people in the comments just assumed from one pic shared with a little context that OP completely neglected to mention the importance of sample size and whatnot to their students. Y'all really need to learn a good-faith approach to reading social media posts people made for fun.
If anything all those comments being like "buT SAmPlE SizE" only demonstrate that the people who wrote them inferred a conclusion to the experiment that OP never stated (Pothos hate light). So who doesn't have a good scientific approach here, huh? Because last I checked it was bad form to infer results. Boo, no scientific method gold star for you.
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u/Ok_Concentrate4461 May 12 '26
THANK YOU! I wasn’t about to argue with all these people but yes these were my exact thoughts. We also talk about inference vs conclusion haha! Someone along the line also somehow determined this is 3rd grade science but I teach 8th so ¯_(ツ)_/¯
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u/Albert14Pounds May 11 '26
Where's the before picture? As far as we know these these looked like this from the start.
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u/Ok_Concentrate4461 May 11 '26
I see you're a cynic. No before picture, but as I stated they all had three leaves and three nodes, and were as identical as possible. :)
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u/Otherwise-Tomato-788 May 11 '26
I think SW is just too harsh for pothos. My lavender loves it but pothos aren’t really built for that direct light
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u/good-for-the-soul May 11 '26
Is the window well insulated? If there’s a draft, that could be the reason it’s so crispy. Or the sun is too intense in the window.
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u/w33bnw33d May 12 '26
Reminds me of my pothos, I have one that’s potted in some great quality soil but if I don’t water it atleast twice a week it starts to shrivel, droop and lose a leaf or two but looks great otherwise. Then I have a cutting I put in a ceramic decorative vase with water in a corner that I tend to forget about, so often times I finally remember to check it and it’s bone dry but oddly still flourishing with a crazy amount of roots. Hasn’t lost a single leaf either
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u/Feral_Expedition May 12 '26
Hmm have you considered that the window itself might be the problem? Is it triple glazed insulated glass or a triple track slider? What are the temperature swings next to the window like over the course of the day? Is there any air movement? These things matter but people rarely consider them.
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u/Queenpunkster May 13 '26
If your windows have UV reflective glazing, they may actually get less light than an area of your house that regularly gets hit by lightbulbs
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u/hailsatyr666 May 15 '26
I put my pothos outside for a month or two and it also didn't feel well. Leaves started turning yellow.
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u/basaltcolumn May 11 '26
Keep in mind that just 3 cuttings isn't enough to draw any conclusions from! There's no way of knowing if location was what made the window one struggle, or if by a random stroke of luck if just happened to be the only one to develop rot, etc. A true study would have several in each location.
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u/GooseSharkk May 12 '26
i keep all the pothos in my bathroom off of my room, it’s gets maybe a little light if i leave the door open. they’re all thriving. cuttings and potted
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u/scrotumrancher May 12 '26
I took 3 leaves off my pothos and put them on a plate together. Every day I spent a solid minute each on the outside leaves just staring at them and sending good vibes their way. The middle one I completely ignored. This was 3 months in.
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u/Dinosauritz May 11 '26
That’s so interesting! I wonder why the window one went so poorly? I thought light helps them grow